A conceptual biorefinery process has been designed for the integration of the protein extraction and the ethanol production from brewers’ spent grain (BSG) and palm kernel meal (PKM). The conceptual process is designed for an industrial scale biorefinery annually processing 20 kton dry weight BSG and 50 kton dry weight PKM with 8000 production hours per year and is used to techno-economically analyse the performance. The techno-economic analysis showed that the biorefinery of BSG has a high economic potential with an internal rate of return of 24 %. However, despite the high raw material costs, the biorefinery of PKM still has a positive internal rate of return of 12 %. The presented virtual biorefinery demonstrated the economic potential of integrating the production of a valuable product, like protein powder for food applications, with the production of biofuel, like ethanol, from the remaining biomass, thereby valorising a larger portion of the biomass with the same raw material costs.